﻿// 重写这个方法，忽略为空的关联数据
Ext.override(Ext.data.reader.Reader, {
	extractValues : function(data) {
		var fields = this.getFields(), i = 0, length = fields.length, output = {}, field, value;

		for (; i < length; i++) {
			field = fields[i];
			try {
				value = this.extractorFunctions[i](data);
			} catch (e) {
				value = null;
			}

			output[field.name] = value;
		}

		return output;
	}
});